Information data processing apparatus

ABSTRACT

A signal processing apparatus of a configuration capable of requesting a transmission of an information file including the currently received information data in response to an instruction for starting a recording in the course of reception of information data transmitted from a transmitting apparatus and decoding of the information data by a decoder, and receiving the information file transmitted from the transmitting apparatus in response to the transmission request, while suspending the decoding process by the decoder.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a data processing apparatus, andmore particularly to a communication process for information data.

[0003] 2. Related Background Art

[0004] Recently equipment for recording digital image data of a movingimage or a still image, such as a digital camera or a digital videocamera, is becoming popular.

[0005] In the digital camera, a compact memory card is widely employedas the recording medium, and there is also available the camera of atype capable of recording moving image data in addition to still imagedata.

[0006] In the digital video camera, a magnetic tape is widely employedas the recording medium. In addition, there is also available the cameraof a type utilizing a recording medium capable of random access such asa compact memory card or a magnetooptical disk, thereby being capable ofrecording not only moving image data but also still image data. Thedigital video camera utilizing such random accessible recording mediumis arranged to store the image data in a file format.

[0007] In such equipment, transferring image data through a cableconnected to another equipment is commonly practiced, and in particular,a data transfer format called IEEE 1394 interface is widely utilized inthe digital video camera.

[0008] The IEEE 1394 interface is featured by including, as the transfermodes, an asynchronous transfer mode (non-synchronized transfer mode)for transferring non-synchronized data, and an isochronous transfer mode(synchronized transfer mode) for transferring synchronized data such asreal-time video stream data.

[0009] The isochronous transfer mode is effective for transferring dataa predetermined data amount of which is required to be transferredcontinuously at a constant transfer rate, such as moving image streamdata. For example, in case of connecting a digital video camera and apersonal computer (PC) through an IEEE 1394 interface, it is madepossible, by utilizing the isochronous transfer mode, to cause the PC todecode the image data transferred from the digital video camera to thePC and to display such image data on real-time basis on a monitor of thePC.

[0010] On the other hand, the asynchronous transfer mode is effectivefor transferring data that is required to be transferred to a designatednode in non-synchronous manner, for example a control command or filedata. Also in the asynchronous transfer mode, there can be made aresponse indicating that a receiving operation has been executed, sothat the communication can be executed more securely than in theisochronous transfer mode. In case of transmitting or receiving theimage data by the digital video camera on real-time basis utilizing theIEEE 1394 interface, it is common to utilize the isochronous transfermode. Also the asynchronous transfer mode is incapable of ensuringtransfer of moving image data or the like at a predetermined timing, andis therefore unsuitable for the transfer of data which may be requiredto be decoded and monitored in the course of reception thereof, such asmoving image stream data.

[0011] For example, there is widely available an application softwarewhich, in case of connecting a digital video camera and a PC through anIEEE 1394 interface, attains that the PC decodes the image datatransmitted from the digital video camera to the PC by the isochronoustransfer mode, to be displayed in real-time. There is also available anapplication software which attains to store the image data transmittedto the PC in the isochronous transfer mode, in a hard disk of the PC inresponse to a user instruction thereby preparing a moving image datafile.

[0012] It is also commonly executed to connect two digital video cameraswith an IEEE 1394 interface to execute a dubbing of the image datautilizing the isochronous transfer mode.

[0013] However, in case of recording an image data stream transferred inthe real-time transfer mode, onto a recording medium, there remains apossibility, as a problem, that the image data stored in the recordingmedium of the equipment at the transmitting side do not completelycoincide with the image data recorded in the equipment of the imagereceiving side.

[0014] For example, in case of connecting a digital video camera whichhandles the image data on the recording medium as an image data file,with a PC through an IEEE 1394 and storing as a file in the PC the imagedata transmiferred from the video camera in the isochronous mode, the PCinitiates the recording of the image data from a position where thestart of recording is instructed, so that the moving image data may notcompletely coincide in a start portion or an end portion of such movingimage data between recording medium and the PC.

[0015] As a result, the image data file recorded in the PC becomesdifferent from the original image data file present on the recordingmedium of the digital video camera.

[0016] Also, the isochronous transfer mode, which has a real-timeproperty, is suitable for transferring data which include time-relatedinformation such as moving image data or audio data, but is unsuitablefor transferring still image data.

[0017] In case of transferring still image data in the isochronoustransfer mode, the transfer has to be executed after such still imagedata is converted into a format corresponding to moving image data. Forthis reason, the receiving side receives image data which is differentfrom the original image data.

[0018] Also, even in case of transferring moving image data, the imagedata format that can be transferred in the isochronous transfer mode islimited in certain equipment, so that there is anticipated a situationwhere the image data to be transferred has to be converted into atransferrable format before the transmission can be made.

[0019] As explained in the foregoing, in case of transmitting the imagedata as a continuous stream by a real-time transfer method such as theisochronous transfer mode,-there results in a possibility that thetransferred image data are different from the original image data. Suchpossibility is not limited to the case of connecting the digital videocamera and the PC but may appear in all the image data exchangeutilizing the real-time transfer method.

[0020] Also in case of receiving and storing the image data utilizingthe real-time transfer method, the stored image data file becomesdifferent from the original image data file. Such storage of image datafile may be different from what is intended by the user, and may cause aconfusion.

SUMMARY OF THE INVENTION

[0021] An object of the present invention is to solve the aforementioneddrawbacks.

[0022] Another object of the present invention is to enable, by a simpleoperation, reception of an image data file in a format same as that ofan original image data.

[0023] The above-mentioned objects can be attained, according to anaspect of the present invention, with a signal processing apparatusincluding:

[0024] instruction means;

[0025] a decoder for decoding an information data stream;

[0026] communication means for receiving the information data streamtransmitted from a transmitting apparatus;

[0027] a storage for storing the information data stream received by thecommunication means, wherein the communication means has a first modefor receiving the information data while decoding the information data,and a second mode for receiving the information data while suspendingthe decoding of the information data; and

[0028] control means for requesting the communication means to transmitan information data file including the information data stream inresponse to an instruction provided by the instruction means in thecourse of reception of the information data stream in the first mode,and controlling the communication means so as to receive in the secondmode the information data file transmitted from the transmittingapparatus, in response to the transmission request.

[0029] Still other objects of the present invention, and the featuresthereof, will become fully apparent from the following detaileddescription of the embodiments, to be taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0030]FIG. 1 is a view showing the configuration of a data processingsystem in which the present invention is applied;

[0031]FIG. 2 is a flow chart showing a data receiving operation of anembodiment of the present invention;

[0032]FIG. 3 is a flow chart showing a data receiving operation of anembodiment of the present invention;

[0033]FIG. 4 is a view showing another configuration of the dataprocessing system in which the present invention is applied;

[0034]FIG. 5 is a flow chart showing a data receiving operation of anembodiment of the present invention; and

[0035]FIG. 6 is a flow chart showing a data receiving operation of anembodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0036]FIG. 1 is a block diagram showing the configuration of a system ofthe present invention, constructed with a digital video camera. In animage recording-reproducing system of the present embodiment, as shownin FIG. 1, digital video cameras 100, 200 of a same configuration areconnected by a digital interface. The digital video camera 100 and thedigital video camera 200 have similar functions, and each has both animage transmitting function and an image receiving function providedwith a digital interface.

[0037] In the following there will be explained a case where the digitalvideo camera 100 functions as an apparatus of a receiving side while thedigital video camera 200 functions as an apparatus of a transmittingside.

[0038] Also the present embodiment employs IEEE 1394 as the digitalinterface, and function control protocol (FCP) as a protocol fortransmitting and receiving a control command. The FCP transmits variouscommand data and response data in the asynchronous transfer mode.

[0039] The digital video camera 100 has a function of transmitting tothe image transmitting apparatus, a current file acquisition command foracquiring an original image data file which is an original of image datareceived in the isochronous transfer mode.

[0040] Also the digital video camera 200 has a function of receiving thecurrent file acquisition command and transmitting in the asynchronoustransfer mode a file including the image data transmitted in theisochronous transfer mode.

[0041] In the digital video camera 100 shown in FIG. 1, there areprovided a camera unit 101 for converting an optical image of an objectinto an electrical signal; an A/D converter 102; an image processingunit 103 for converting digitized image data into a digital image dataof a predetermined format; and an encoder 104 for encoding the digitalimage data according to a predetermined encoding method to compress theinformation amount. In the present embodiment, the image data is encodedaccording to the MPEG2 method.

[0042] A disk I/F 105 executes recording and reproduction of image datain and from a disk D1. A digital interface (DIF) 106 is composed of anIEEE 1394 interface in the present embodiment, for example. Adisk-shaped recording medium D1 capable of random access, such as forexample a DVD-RAM or an MO, can record digital data such as moving imagedata, still image data or audio data, as a data file.

[0043] There are also provided a decoder 107 capable of decoding theencoded digital data; a D/A converter 108; a monitor 109 constitutingdisplay means; control means 110 for controlling the function of thevideo camera 100 and provided with a microcomputer; a writable memory111 for storing program codes readable by the control means 110; anoperation unit 112 composed for example of an operation panel, a remotecontroller etc.; and a terminal 113 for connecting the DIF 106 and anIEEE 1394 interface of an external equipment.

[0044] The video camera 200 shown in FIG. 1 has a configuration similarto that of the video camera 100, so that the detailed configuration ofthe video camera 200 will not be explained further.

[0045] In the following there will be given an explanation on thefunction of the video camera 100 and the video camera 200 shown in FIG.1.

[0046] The video camera 100 and the video camera 200 respectively have areproducing mode for reproducing the image data recorded in the disks D1and D2, and a recording mode for recording as an image data file imagedata obtained by the camera unit or image data entered from the DIF.

[0047] The control means of each of the video camera 100 and the videocamera 200 controls the function of each DIF so as to have an imagetransmitting function in case of the reproducing mode and an imagereceiving function in case of the recording mode. In the following,there will be explained, as an example, a case where the video camera100 functions in the recording mode and the video camera 200 functionsin the reproducing mode.

[0048] At first there will be explained the function of the video camera100 in the recording mode.

[0049] The camera unit 101 converts the optical image of an object intoan electrical signal and supplies the A/D converter 102 with suchelectrical signal. The A/D converter 102 converts the electrical signalreceived from the camera unit 101, into a digital signal. The imageprocessing unit 103 converts the digitized image data into digital imagedata of a predetermined format and sends the converted image data to theencoder 104 and the D/A converter 108. The encoder 104 encodes thedigitized image data and transfers them to the disk I/F 105.

[0050] In the recording mode, the DIF 106 can receive the image data inthe isochronous transfer mode. In case of receiving the image data inthe isochronous transfer mode, the DIF 106 transmits the image data tothe decoder 107 and informs the control means 106 of the reception ofthe image data in the isochronous transfer mode. In this manner, in theisochronous transfer mode, decoding and display is executed whilereceiving the image data.

[0051] The DIF 106 can also transmit according to an instruction of thecontrol means 110, a control command to another node (device) on theIEEE 1394 serial bus connected through the terminal 113. It can alsoreceived the image data file in the asynchronous transfer mode, byissuing a current file acquisition command which is one of the controlcommands and is used for acquiring in the asynchronous transfer mode afile of the image data currently in reception in the isochronoustransfer mode. The image data file received in the asynchronous transfermode is transferred to the disk I/F 105.

[0052] The operation unit 112 sends an operation instruction to thecontrol means 110, according to a user operation for example for arecording of the image data from the camera unit 101 or a stoppingthereof. For example, in case a recording operation is executed by theuser, the operation unit 112 sends a recording instruction to thecontrol means 110. Also in case of a stopping operation, it sends astopping instruction to the control means 110.

[0053] According to the instruction from the operation unit 112, thecontrol means 110 controls the recording-reproducing operation by thedisk I/F 105 and gives an instruction for transmitting a control commandor another instruction to the DIF 106.

[0054] In case the reception of the image data in the isochronoustransfer mode is not in progress when the recording instruction isprovided from the operation unit 112, the control means 110 controls thedisk I/F 105 so as to record the image data from the encoder 104. Alsothe control means 110 sends a recording stop command to the disk I/F 105in response to a stop instruction from the operation unit 112.

[0055] The disk I/F 105 is provided with a laser pickup, a magnetichead, and a mechanism for rotary driving the disk D1 as already known,and, upon receiving a recording instruction from the control means 110,records on the disk D1 the image data outputted from the encoder 104when such the instruction is received. In the present embodiment, aseries of moving image data recorded in the disk D1 during a period fromthe start of recording to the stopping of recording is recorded as amoving image file on the disk D1.

[0056] Also in case a file recording is instructed by a key manipulationon the operation unit 112 by the User in the course of reception of theimage data by the DIF 106 in the isochronous transfer mode, the controlmeans 110 instructs the DIF 106 to transmit a current file acquisitioncommand. In response to the instruction from the control means 110, theDIF 106 generates a current file acquisition command for requesting toan external equipment the transmission in the asynchronous transfer modeof a file including the image data currently received in the isochronoustransfer mode, and outputs such command to the video camera 200 which isthe transmitting apparatus.

[0057] In response to such current file acquisition command, the videocamera 200 of the transmitting side reproduces an image file includingthe image data currently transmitted to the isochronous transfer mode,from the disk D2 and transmits such image file to the DIF 106 of thevideo camera 100 by the asynchronous transfer mode. In the asynchronoustransfer mode, the image data file is transferred at a timing irrelevant(non-synchronized) to the timing of reproduction or decoding of theimage data. Also different from the image data received in theisochronous transfer mode, the image data received in the asynchronoustransfer mode is not subjected to a process of decoding or display.Stated differently, the asynchronous mode is a mode of receiving theimage data without executing the decoding or the display in the courseof reception.

[0058] The disk I/F 105, in case of acquiring the image data filereceived by the DIF 106 in the asynchronous transfer mode, records suchimage data file in the disk D1. Also the disk I/F 105, upon receiving astop command from the control means 110 in the source of recording ofthe image data from the encoder 104, terminates the recording of theimage data on the disk D1.

[0059] In the recording mode, the moving image data received by the DIF106 in the isochronous transfer mode is outputted to the decoder 107which decodes the image data received from the DIF 106 and outputs thedecoded data to the D/A converter 108.

[0060] The D/A converter 108 converts the received data into an analogsignal. In case the image data is received from both the imageprocessing unit 103 and the decoder 107, the control means 110 controlsthe D/A converter 108 so as to select and output the image datatransferred from the decoder 107.

[0061] The monitor 109 displays an image corresponding to the analogimage signal supplied from the D/A converter 108.

[0062] The above-described configuration allows the video camera 100 torecord the image data being received in the isochronous transfer mode,as a file.

[0063] In the following there will be given a detailed description onthe recording process of the image data in the video camera 100, withreference to a flow chart shown in FIG. 2 which illustrates a flow chartshowing the process of the control means 110 in the recording mode.

[0064] Referring to FIG. 2, a step S201, in case the DIF 106 isreceiving the image data in the isochronous transfer mode, decodes thereceived image data in the decoder 107 and displays the image data onthe monitor 109, but, in case the image data are not received, displaysthe image data picked up by the camera unit 101 on the monitor 109.

[0065] A step S202 discriminates whether or not an image data recordingis instructed by the user. In case of absence of the recordinginstruction, the sequence returns to the step S201 to repeat the displayprocess of the image data. In case of presence of the recordinginstruction, the sequence proceeds to a step S203.

[0066] A step S203 discriminates whether or not the image data is beingreceived in the isochronous transfer mode, and, in case the image datarecording is instructed from the user in the course of reception of theimage data in the isochronous transfer mode, the sequence proceeds to astep S204. A step S204 so controls the DIF 106 as to transmit a currentfile acquisition command in order to acquire the file of the image datacurrently received in the isochronous transfer mode.

[0067] Then a step S205 receives the image data file in the asynchronoustransfer mode as a response to the current file acquisition commandtransmitted in the step S204, and records the data file in the disk D1.

[0068] When all the data of the image data file are recorded, thecontrol means 110 displays information indicating this, on the monitor109. In the present embodiment, even after receiving the current fileacquisition command from the video camera 100, the: video camera 200continues the transmission of the image data in the isochronous transfermode while transferring the image data file in the asynchronous transfermode. However, the control means 210 of the video camera 200 may be soconstructed as to terminate the transfer of the image data in theisochronous transfer mode in case of receiving the current fileacquisition command from the video camera 100.

[0069] Also in case the image data is not being received in theisochronous transfer mode in the step S203, the sequence proceeds to astep S206 to record the image data picked up by the camera unit 101, onthe disk D1. In such case, as explained in the foregoing, the image datarecording on the disk D1 is terminated in response to a recording stopcommand.

[0070] The above-described process allows to acquire and record theimage data file including the image data currently received in theisochronous transfer mode.

[0071] In the following there will be explained the function of thevideo camera 200 in the reproducing mode.

[0072] In the reproducing mode, the video camera 200 can reproduce theimage data recorded in the disk D2, with the disk I/F 205 and transmitthe image data to the video camera 100 with the DIF 206 in theisochronous transfer mode. The DIF 206 also receives a control commandtransmitted from another node. In case of receiving a control command,the DIF 206 transmits such control command to the control means 210.

[0073] In the disk D2, there are recorded files of digital data such asa moving image data file, a still image data file, an audio data etc.

[0074] The operation unit 212 sends an instruction for operation, suchas reproduction or stopping, to the control means 210 according to anoperation of the user. For example, in case a reproducing operation isexecuted by the user, the operation unit 212 transmits a reproducinginstruction to the control means 210. Also in case a stopping operationis executed, the operation unit 212 transmits a stopping instruction tothe control means 210.

[0075] The control means 210 receives an instruction from the operationunit 212 and a control command from the DIF 206, also controls thefunction of the disk I/F 205 and controls the data transfer process ofthe DIF206.

[0076] The control means 210, upon receiving a reproducing instructionfrom the operation unit 212, instructs the disk I/F 205 to reproduce theimage data. According to the instruction from the control means 210, thedisk I/F 205 reproduces-the image data recorded in the disk D2, andoutputs the image data to the decoder 207 and the DIF 206. At thereproduction of the image data from the disk D2, the control means 210retains information of a file path name for specifying the image filecurrently under reproduction.

[0077] The reproduced image data is decoded by the decoder 207 and isdisplayed on the monitor 209 through the D/A converter 208. Also thecontrol means 210 controls the DIF 206 to transmit the reproduced imagedata to the video camera 100 in the isochronous transfer mode.

[0078] Also in case a current file acquisition command is transferredthrough the DIF 206 as explained in the foregoing, the control means 210instructs, utilizing the memorized file path name of the currentlyreproduced image data, the disk I/F 205 to reproduce an image fileincluding the currently reproduced image data.

[0079] The disk I/F 206, upon receiving a current file transmittingcommand from the control means 210, reads an image data file of thedesignated file path name from the disk D2 and outputs the read-out fileto the DIF 206. The control means 210 controls the DIF 206 and transmitsthat image data file to the video camera 100 in the asynchronoustransfer mode.

[0080] In the present embodiment, as explained in the foregoing, in casethe user instructs the recording of the image data in the course ofreception of the image data in the real-time transfer mode, the transferof an original image data file including that image data is requested tothe transmitting equipment. Then, in response to such the request, thetransmitting equipment transmits the image file including the currentlytransmitted image data, in the file transfer mode.

[0081] In the present embodiment, therefore, an image data fileconstituting the origin of the image data currently received in thereal-time transfer mode can be securely acquired. It is thus renderedpossible to transfer and record an image data file in a format same asthat of the original image data, and to record the image data file in aformat desired by the user.

[0082] In the present embodiment, there has been explained a case oftransmitting an image data file between the video cameras 100 and 200,but the present invention is applicable also to a case of transmittingplural image data file recorded in the disk D2 to the video camera 100.

[0083] In the following there will be explained a process in case pluralimage data files are recorded in the disk D2.

[0084]FIG. 3 is a flow chart showing the function of the control means110 in case of receiving plural image data files recorded in the diskD2, by the video camera 100.

[0085] At first, in a step S301, the video camera 200 transfers one ofthe image data files recorded in the disk D2, to the video camera 100 inthe isochronous transfer mode, and the video camera 100 receives theimage data transmitted in the isochronous transfer mode and displays thereceived image data on the monitor 109.

[0086] In this state, a step S302 detects whether a recordinginstruction by the operation unit 112 is present or absent, and, in casea recording instruction is present, a step S303 transmits a current fileacquisition command from the DIF 106 to the video camera 200 asexplained in the foregoing. Then, in a step S304, an image data filetransmitted from the video camera 200 and including the currentlyreceived image data, is received in the asynchronous transfer mode andis recorded onto the disk D1 by the disk I/FF 105.

[0087] Then, in a step S305, the DIF 106 outputs, to the video camera200, a command requesting the transmission of image data contained in anext image data file. Then, in case a step S306 identifies that astopping instruction for the reception is not given by the operationunit 112, the sequence returns to the step S301 to receive image datatransmitted from the video camera 200 and contained in the next imagedata file, in the isochronous transfer mode.

[0088] Also in case the recording instruction is absent in the stepS302, a step S307 detects whether an instruction to skip from thecurrently received image data to a next image data file is given by theoperation unit 112. In case a skipping request is present, the sequenceproceeds to the step S305 to output from the DIF 106 to the video camera200 a command for requesting transmission of image data contained in thenext image data file recorded in the disk D2. In case the skippingrequest is absent in the step S307, the sequence returns to the stepS301.

[0089] In case an instruction for stopping the reception is given fromthe operation unit 112 in a step S306, the process is terminated.

[0090] In the embodiment shown in FIG. 3, as explained in the foregoing,in case a recording instruction is given for the image data currentlyreceived in the isochronous transfer mode in the course of receiving theplural image data files recorded in the disk D2, by the video camera100, a transfer request for an image data file including the currentlyreceived image data is outputted to the transmitting apparatus and thenthat image data file is received in the asynchronous transfer mode,whereby it is rendered possible to transfer and record the image datafile in a format same as that of the original image data.

[0091] In addition, the present embodiment, after receiving and storingan image data file in the asynchronous transfer mode, automaticallyoutputs a command requesting reproduction and transmission of a nextimage data file recorded in the disk D2, and is therefore veryconvenient in case of receiving and recording in succession plural imagedata files recorded in the disk D2.

[0092] Also in case the image data received and displayed in theisochronous transfer mode need not be recorded, it is only required toissue a skipping instruction whereby a request for transmission of theimage data contained in the next image data file is automaticallyoutputted and the reception in the isochronous transfer mode isinitiated, and this configuration therefore is very convenient in caseof receiving in succession plural image data files recorded in the diskD2.

[0093] In the video camera shown in FIG. 1, the recording andreproduction of the image data are executed on a disk medium, but thepresent invention is applicable to and is similarly effective in anapparatus for recording and reproducing information data such as imagedata on another recording medium for example a random accessible mediumsuch as a memory card.

[0094] Also in the present embodiment, in case the DIF 106 in the videocamera 100 is receiving an image data stream in the isochronous transfermode, an image according to the image data from the DIF 106 instead ofthe image data from the camera unit 101 is displayed on the monitor 109and the image file including the image data from the DIF 106 is recordedin the disk D1. However, there may also be adopted a configuration inwhich image data selected in advance by the user among the image datafrom the camera unit 101 and those from the DIF 106 are recorded in thedisk D1 and displayed on the monitor 109.

[0095] In the following there will be explained a second embodiment ofthe present invention.

[0096]FIG. 4 is a block diagram showing the configuration of arecording-reproducing system of the present invention, composed of a PC300 and a video camera 200. Also in the present embodiment, the PC 300and the video camera 200 are connected by an IEEE 1394 interface, andFCP is employed as the protocol for transmitting and receiving controlcommands.

[0097] The PC 300 of the present embodiment has a function oftransmitting to the apparatus of the transmitting side, a path nameacquisition command for acquiring a path name of an image data filereceived in the isochronous transfer mode and a file acquisition commandfor acquiring a data file.

[0098] The video camera 200 of the present embodiment has aconfiguration and functions explained in the foregoing embodiment, andalso has a function of receiving the path name acquisition commandrelating to the file path name of the image data file transmitted in theisochronous transfer mode and transmitting the path name of the imagedata file, and a function of receiving the fine acquisition command foracquiring the image data file and transmitting the image data file inthe asynchronous transfer mode.

[0099] In the PC 300 shown in FIG. 4, there are provided a processingapparatus (CPU) 301 for controlling the function of the PC 300, adisplay 302 such as a CRT or a liquid crystal display panel, and a harddisk (HDD) 303 for recording digital data such as program data, movingimage data, still image data, audio data etc. The hard disk 303 storesan image data acquisition application to be explained later, in the formof program codes readable by the CPU 301.

[0100] There are also provided an internal memory 304, a decoder 305 fordecoding encoded moving image data, still image data, audio data etc.,an operation unit 306 composed of a keyboard, a mouse etc., a digitalinterface 307 for executing transmission and reception of digital datawith an external apparatus and composed of an IEEE 1394 interface in thepresent embodiment for example, an internal bus 308 such as a PCI busfor connecting various processing units in the PC 300, and a terminal309 for connecting the DIF 307 with an external equipment.

[0101] As shown in FIG. 4, the PC 300 and the video camera 200 areconnected by an IEEE 1394 interface. In the following there will beexplained functions and operations of the processing units constitutingthe PC 300. In the present embodiment, the PC 300 functions as an imagereceiving apparatus for receiving image data transmitted from the videocamera 200.

[0102] The CPU 301 executes a software recorded in the HDD 303, andtransfers various data to the internal memory 304. The CPU 301 alsocontrols the function of the processing units connected by the internalbus 308.

[0103] The DIF 307 can receive image data transferred through the IEEE1394 bus. The DIF 307 can also transmit a control command to anothernode on the IEEE 1394 serial bus.

[0104] The user selects a desired application by manipulating theoperation unit 306, and causes the CPU 301 to execute the applicationrecorded in the HDD 303. In this operation, the information relating tothe application is presented by the display 302 to the user. Also theuser can execute an operation on the application by manipulating theoperation unit 306. For example the user can execute an image dataacquiring application and thereby can instruct a storage process for thereceived image data.

[0105] The decoder 305 decodes the image data outputted from the DIF 307based on the function of the application. The decoded image data isdisplayed on the display 302. The decoding process may also be executedby an application recorded in the HDD 303.

[0106] In the following, there will be explained, with reference to aflow chart shown in FIG. 5, the operation of the image data acquiringapplication in case the PC 300 receives, with the DIF 307 in theisochronous transfer mode, image data reproduced from the disk D2 in thevideo camera 200.

[0107]FIG. 5 is a flow chart showing a control operation by the CPU 301in the PC 300.

[0108] Referring to FIG. 5, a step S501 receives the image datatransmitted in the isochronous transfer mode and causes the decoder 305to decode the received image data and display the image data on thedisplay 302.

[0109] Then a step S502 discriminates whether or not a storageinstruction for the image data is given from the user, and, if not, thesequence returns to the step S501 to repeat the display process of thereceived image data.

[0110] In case a storage of the image data is instructed from the userin the course of reception of the image data in the isochronous mode,the CPU 301 controls the DIF 307 in a step S503, thereby transmitting tothe video camera 200 a path name acquisition command for searching thepath name of the file of the currently received image data. In responseto this path name acquisition command, the video camera 200 transmitsthe file path name of the image data to the PC 300. In a step S504, thefile path name is received by the DIF 307.

[0111] Then, in a step S505, a file acquisition command includinginformation of the file path name acquired in the step S504 istransmitted from the DIF 307 to the video camera 200, in order torequest transmission of an image data file including the image datacurrently received in the isochronous transfer mode. The video camera200 reproduces, from the disk D2, an image data file of the file pathdesignated by file acquisition command as will be explained later, andtransmits the image data file in the asynchronous transfer mode. Then,in a step S506, the DOF 307 receives the image data file thustransmitted in the asynchronous transfer mode and stores it in the HDD303.

[0112] In the following there will be explained the function of thevideo camera 200.

[0113] The ordinary recording and reproducing operations are same asthose in the foregoing embodiment, and, in the reproducing mode, imagedata is transmitted in the isochronous transfer mode from the DIF 206 tothe PC 300.

[0114] When a path name acquisition command is transmitted from the PC300 through the DIF 206, the control means 210 issues a path nameacquisition instruction to the disk I/F 205. Upon receiving the pathname acquisition instruction from the control means 210, the disk I/F205, if in the course of reading the image data from the disk D2,retains information of the path name of the currently read image datafile and causes the DIF 206 to transmit the information of the path namein the asynchronous transfer mode to the PC 300.

[0115] Also when a file acquisition command is sent from the PC 300through the DIF 206, the control means 210 issues a reproducinginstruction of the image data file to the disk I/F 205 and so controlsthe DIF 206 to terminate the file data transfer in the isochronoustransfer mode. The disk I/F 205 reproduces a designated image data filefrom the disk D2 and so controls the DIF 206 to transmit the reproducedimage data file to the computer 200 in the asynchronous transfer mode.

[0116] The present embodiment is so constructed as to terminate inadvance the data transfer in the isochronous transfer mode in case offile transfer in the asynchronous transfer mode, but there may also beemployed such a configuration as not to terminate the data transfer inthe isochronous transfer mode.

[0117] Thus, also in the present embodiment, in case a storageinstruction of the image data is given by the user in the course ofreception of the image data in the real-time transfer mode by thecomputer, there is requested a transfer of the original image data fileincluding such image data, to the transmitting equipment. In response tothis request, the transmitting equipment transmits the image data fileincluding the currently transmitted image data, in the file transfermode.

[0118] In the present embodiment, therefore, an image data fileconstituting the origin of the image data currently received in thereal-time transfer mode can be securely acquired.

[0119] In the following there will be explained a third embodiment ofthe present invention.

[0120] The present embodiment has a system configuration same as thatshown in FIG. 4, and executes processes similar to those in the secondembodiment except for an image data acquisition process in case thecomputer 300 is in the course of receiving the image data from the DIF307 in the isochronous transfer mode, so that detailed description willbe omitted except for this process.

[0121] In the following there will be given a detailed description, withreference to a flow chart shown in FIG. 6, on the function of an imagedata acquiring application in case the PC 300 is receiving the imagedata by the DIF 307 in the isochronous transfer mode.

[0122]FIG. 6 is a flow chart showing the control function of. the CPU301 in an image data receiving process.

[0123] Referring to FIG. 6, steps S601 to S604 are similar to the stepsS501 to S504 in FIG. 5.

[0124] Then a step S605 detects the form of the image data fileincluding the image data on the basis of a file extension contained inthe file path name acquired in the step S604, and judges the receivingmethod. More specifically, in case the file extension is an extensionindicating a still image (for example jpg or jpeg), the sequenceproceeds to a step S606, but, in case of any other extension, thesequence proceeds to a step S608.

[0125] In the present embodiment, the JPEG extension is referred to asan example of the file extension for identifying a still image, butanother extension may be used for such judgment. Also in the presentembodiment, the format of the image is judged with the extension of thefile, but there may also be employed another method for such thejudgment.

[0126] In case the step S605 identifies that the image data received inthe isochronous transfer mode is data of a still image file, a fileacquisition command including the information on the file path nameacquired in the step S604 is transmitted from the DIF 307 to the videocamera 200, in order to request a transmission of the image data fileincluding the image data currently received in the isochronous transfermode. The video camera 200 reproduces, from the disk D2, an image datafile of the file path designated by the file acquisition command, andtransmits the image data file in the asynchronous transfer mode. Then,in a step S607, the image data file transmitted in the asynchronoustransfer mode is received by the DIF 307 and is stored in the HDD 303.

[0127] In case the image data file including the image data received inthe isochronous transfer mode is not a still image file, a step S608stores the image data received in the isochronous transfer mode.

[0128] In the present embodiment, as explained in the foregoing, whilereceiving the image data in the real-time transfer mode, the image datais acquired still in this real-time transfer mode in case the image datafile including that image data is a moving image data file, but theimage data file is acquired in the file transfer mode in case the imagedata file is a still image data file.

[0129] Therefore the user is not required to distinguish whether thefile format of the image data received in the real-time transfer mode isa moving image data format or a still image data format, and the usercan acquire the desired image data with a similar operation in eitherformat.

[0130] In the foregoing third embodiment, in case the format of theimage data transmitted in the real-time transfer mode is a still imagefile, the still image file is received in the asynchronous transfermode, but there may be also adopted a configuration which, in case theformat of the image data contained in the original image file isconverted and transmitted in the isochronous transfer mode, compares theformat of the currently received image data with the format of theoriginal image data file and, if these formats are mutually different,requests a transmission of the original image data file in theasynchronous transfer mode.

[0131] In the foregoing embodiments, there has been explained a systemwhich transmits and receives the image data utilizing the IEEE 1394interface, but the present invention is likewise applicable to a systemexecuting transmission and reception of information data with acommunication interface which is provided with a mode of executingdecoding and monitoring of the information data on real-time basis inthe course of transmission/reception of the information data, and a modeof executing decoding and monitoring of the information data at a timingnot in the course of reception of the information data.

[0132] Also in the foregoing embodiments, there has been explained atransmission/reception.process of image data, but the present inventionis likewise applicable to a case of transmitting and/or receiving otherinformation data, such as audio data.

[0133] Furthermore, the functions explained in the foregoing embodimentsmay also be realized by a computer, and, in such case, a memory mediumstoring an operation program therefor is included also in the presentinvention.

[0134] The embodiments of the present invention explained in theforegoing allow to securely obtain an image data file which constitutesan origin of image data currently received in the real-time transfermode. It is thus rendered possible to transfer and record the image datafile in a format same as that of the original image data, and the imagedata file can be stored in a format desired by the user.

[0135] Many widely different embodiments of the present invention may beconstructed without departing from the spirit and scope of the presentinvention. It should be understood that the present invention is notlimited to the specific embodiments described in the specification,except as defined in the appended claims.

What is claimed is:
 1. A signal processing apparatus comprising:instruction means; a decoder for decoding an information data stream;communication means for receiving the information data streamtransmitted from a transmitting apparatus, wherein said communicationmeans has a first mode for receiving the information data while decodingthe information data, and a second mode for receiving the informationdata while suspending the decoding of the information data; storingmeans for storing the information data stream received by saidcommunication means; and control means for requesting said communicationmeans to transmit an information data file including the informationdata stream in response to an instruction provided by said instructionmeans in a course of reception of the information data stream in thefirst mode, and controlling said communication means so as to receive inthe second mode the information data file transmitted from saidtransmitting apparatus, in response to such transmission request.
 2. Anapparatus according to claim 1, further comprising: a storage forstoring the information data; wherein said control means controls saidstorage so as to store the information data file received in said secondmode.
 3. An apparatus according to claim 1, wherein said control meanscontrols, in response to an instruction provided by said instructionmeans, said communication means so as to transmit a file acquisitioncommand for requesting a transmission of the information data file, tosaid transmitting apparatus.
 4. An apparatus according to claim 3,wherein the file acquisition command includes information of a file pathname of the information data file of which transmission is requested. 5.An apparatus according to claim 4, wherein said communication meansreceives information indicating said file path name transmitted fromsaid transmitting apparatus.
 6. An apparatus according to claim. 1,wherein said control means further detects a format of the informationdata file including the information data received in said first mode,and determines, according to a result of the detection, whether or notto request the transmission of the information data file to saidtransmitting apparatus.
 7. An apparatus according to claim 6, whereinsaid control means controls said communication means so as to requestthe transmission of the information data file in case a format of theinformation data file is a predetermined format, and to inhibit therequest for the transmission of the information data file in case saidformat is other than the predetermined format.
 8. An apparatus accordingto claim 6, further comprising: recording means for recording, accordingto an instruction provided by said instruction means, the informationdata received by said communication means in the first mode and theinformation data received by said communication means in the secondmode, in a recording medium; wherein said control means controls saidrecording means so as to record one of the information data received inthe first mode and the information data received in the second mode,according to the format of the information data file.
 9. An apparatusaccording to claim 8, wherein said control means controls saidcommunication means and said recording means so that, in case the formatof the information data file is a predetermined format, the transmissionof the information data file is requested and the information data filetransferred in said second mode in response to the transmission request,is recorded on said recording medium and, in case the format is otherthan said predetermined format, the transmission of the information datafile is not requested and the information data received in said firstmode, is recorded on said recording medium.
 10. An apparatus accordingto claim 6, wherein said communication means receives informationindicating the format of the information data file from saidtransmitting apparatus, and said control means detects the format of theinformation data file on the basis of the received informationindicating the format of the information data file.
 11. An apparatusaccording to claim 3, wherein said control means detects the format ofthe information data file including the currently received informationdata, on the basis of an extension of the information data file.
 12. Anapparatus according to claim 6, wherein the information data includesimage data, and said control means detects whether the image data fileincluding the currently received image data, is a moving image file or astill image file.
 13. An apparatus according to claim 12, wherein saidcontrol means further controls said communication means so as to requestthe transmission of said image data file in case the format of the imagedata currently received in the first mode is different from the formatof the image data file.
 14. An apparatus according to claim 1, whereinsaid communication means receives the information data according to anIEEE 1394 serial bus format, and the first mode is a synchronoustransfer mode defined in said IEEE 1394 serial bus format, and thesecond mode is an asynchronous transfer mode defined in said IEEE 1394serial bus format.
 15. A signal processing apparatus comprising:communication means for receiving information data transmitted from atransmitting apparatus; a decoder for decoding the information data;instruction means; and control means for controlling said communicationmeans and said decoder so as to request to said transmitting apparatus atransmission of an information file including the information datacurrently in the course of reception, when an instruction is provided bysaid instruction means in a course of reception of the information databy said communication means and decoding of the information data by saiddecoder, and to receive the information file transmitted from saidtransmitting apparatus in response to such transmission request, whilesuspending the decoding process by said decoder.
 16. An apparatusaccording to claim 15, wherein said communication means has a firstcommunication mode for receiving the information data while executingdecoding thereof, and a second communication mode for receiving theinformation data while suspending decoding thereof.
 17. An apparatusaccording to claim 16, wherein said communication means transmits acommand indicating a request for the transmission of the informationfile in the second communication mode, to said transmitting apparatus.18. An apparatus according to claim 15, further comprising: recordingmeans for recording the information data on a recording medium; whereinsaid control means controls said recording means so as to record, onsaid recording medium, the information file transmitted in response tosaid transmission request.
 19. An apparatus according to claim 18,wherein said instruction means instructs a start of recording of theinformation data to said recording means.
 20. An apparatus according toclaim 15, wherein said control means controls said communication meansso as to receive the information file transmitted from said transmittingapparatus in response to said transmission request and at a timingasynchronous with the decoding timing of the information data, whilesuspending the decoding process by said decoder.
 21. A signal processingapparatus comprising: communication means for receiving image datatransmitted from a transmitting apparatus; instruction means; storingmeans for storing the image data; display means for displaying an imagecorresponding to the image data; and control means for controlling saidcommunication means and said display unit so as to request to saidtransmitting apparatus a transmission of an image file including theimage data currently in the course of reception, when an instruction isprovided by said instruction means in a course of reception of saidimage data by said communication means and display of said image data bysaid display unit, and to receive the image file transmitted from saidtransmitting apparatus in response to the transmission request to outputthe received image file to said storing means, while suspending thedisplay process by said display unit.
 22. An apparatus according toclaim 21, wherein said communication means has a first communicationmode for receiving the image data while executing display thereof, and asecond communication mode for receiving the image data while suspendingdisplay thereof.
 23. An apparatus according to claim 22, wherein saidcommunication means transmits a command indicating a request for thetransmission of the image file in the second communication mode, to saidtransmitting apparatus.
 24. An apparatus according to claim 22, whereinsaid instruction means instructs a start of recording of the informationdata to said storing means.
 25. An apparatus according to claim 21,wherein said control means controls said communication means so as toreceive the image file transmitted from said transmitting apparatus inresponse to the transmission request and at a timing asynchronous withthe display timing of said image data, while suspending the displayprocess by said display unit.
 26. A signal processing apparatuscomprising: communication means for receiving plural information filesand an information data stream contained in said information files froma transmitting apparatus; instruction means; and control means forcontrolling said communication means so as to request, in response to afirst instruction provided by said instruction means in a course ofreception of the information data stream by said communication means, atransmission of an information file including the information datastream currently in the course of reception, and to request atransmission of another information data stream in said pluralinformation files, other than the currently received information datastream.
 27. An apparatus according to claim 26, wherein said controlmeans controls said communication means so as to request to saidtransmitting apparatus a transmission of the another information datastream without requesting the transmission of the information fileincluding the information data stream currently in the course ofreception, in response to a second instruction provided by saidinstruction means in the course of reception of the information datastream by said communication means.
 28. An apparatus according to claim27, further comprising: recording means for recording the informationdata stream and the information file received by said communicationmeans, on a recording medium; wherein the first instruction is aninstruction for starting recording by said recording means, and thesecond instruction is an instruction for skipping the information datacurrently received by said communication means.
 29. A signal processingapparatus comprising: instruction means; a decoder for decoding aninformation data stream; communication means for receiving theinformation data stream transmitted from a transmitting apparatus,wherein said communication means has a first mode for receiving theinformation data while decoding the information data, and a second modefor receiving the information data while suspending decoding of theinformation data; a storage for storing the information data streamreceived by said communication means; and control means for controllingsaid communication means so as to request in response to an instructionprovided by said instruction means in a course of reception of theinformation data stream in the first mode, a transmission of aninformation data file including the information data stream, to saidtransmitting apparatus and to receive the information data filetransmitted from said transmitting apparatus in response to thetransmission request in the second mode, to output the information datafile to said storage.
 30. A signal processing method comprising: ainstruction step of giving an instruction; a decoding step of decodingan information data stream; a communication step of receiving theinformation data stream transmitted from a transmitting apparatus,wherein said communication step has a first mode for receiving theinformation data while decoding the information data, and a second modefor receiving the information data while suspending the decoding of theinformation data; a storage step of storing the information data streamreceived in said communication step; and a control step of requestingsaid communication step to transmit an information data file includingthe information data stream in response to an instruction provided insaid instruction step in a course of reception of the information datastream in the first mode, and controlling said communication step so asto receive in the second mode the information data file transmitted fromsaid transmitting apparatus in response to the transmission request. 31.A signal processing method comprising: a communication step of receivinginformation data transmitted from a transmitting apparatus; a decodingstep of decoding the information data; an instruction step for giving aninstruction; and a control step of controlling said communication stepand said decoding step so as to request to said transmitting apparatus atransmission of an information file including the information datacurrently in the course of reception, when an instruction is provided insaid instruction step in a course of reception of the information datain said communication step and decoding of the information data in saiddecoding step, and to receive the information file transmitted from saidtransmitting apparatus in response to such transmission request, whilesuspending the decoding process in said decoding step.
 32. A signalprocessing method comprising: a communication step of receiving imagedata transmitted from a transmitting apparatus; an instruction step ofgiving an instructions; a storage step of storing the image data in astorage; a display step of displaying an image corresponding to theimage data; and a control step of controlling said communication stepand said display step so as to request to said transmitting apparatus atransmission of an image file including the image data currently in thecourse of reception, when an instruction is provided in said instructionstep in a course of reception of said image data by said communicationstep and display of said image data by said display step, and to receivethe image file transmitted from said transmitting apparatus in responseto the transmission request to output the received image file to saidstorage, while suspending the display process in said display step. 33.A signal processing method comprising: a communication step of receivingplural information files and an information data stream contained insaid information files from a transmitting apparatus; an instructionstep of giving an instruction; and a control step of controlling saidcommunication step so as to request, in response to a first instructionprovided in said instruction step in a course of reception of theinformation data stream in said communication step, a transmission of aninformation file including the information data stream currently in thecourse of reception, and to request a transmission of anotherinformation data stream in said plural information files, other than thecurrently received information data stream.
 34. A signal processingmethod comprising: an instruction step of giving an instruction; adecoding step of decoding an information data stream; a communicationstep of receiving the information data stream transmitted from atransmitting apparatus, wherein said communication step has a first modefor receiving the information data while decoding the information data,and a second mode for receiving the information data while suspendingdecoding of the information data; a storage step of storing in a storagethe information data stream received by said communication step; and acontrol step of controlling said communication step so as to request inresponse to an instruction provided in said instruction step in a courseof reception of the information data stream in the first mode, atransmission of an information data file including the information datastream, to said transmitting apparatus and to receive the informationdata file transmitted from said transmitting apparatus in response tothe transmission request in the second mode, to output the informationdata file to said storage.
 35. A computer readable memory medium storinga program for a signal processing method, said program comprising: ainstruction step of giving an instruction; a decoding step of decodingan information data stream; a communication step of receiving theinformation data stream transmitted from a transmitting apparatus,wherein said communication step has a first mode for receiving theinformation data while decoding the information data, and a second modefor receiving the information data while suspending the decoding of theinformation data; a storage step of storing the information data streamreceived in said communication step; and a control step of requestingsaid communication step to transmit an information data file includingthe information data stream in response to an instruction provided insaid instruction step in a course of reception of the information datastream in the first mode, and controlling said communication step so asto receive in the second mode the information data file transmitted fromsaid transmitting apparatus in response to the transmission request. 36.A computer readable memory medium storing a program for a signalprocessing method, said program comprising: a communication step ofreceiving information data transmitted from a transmitting apparatus; adecoding step of decoding the information data; an instruction step forgiving an instruction; and a control step of controlling saidcommunication step and said decoding step so as to request to saidtransmitting apparatus a transmission of an information file includingthe information data currently in the course of reception, when aninstruction is provided in said instruction step in a course ofreception of the information data in said communication step anddecoding of the information data in said decoding step, and to receivethe information file, transmitted from said transmitting apparatus inresponse to such transmission request, while suspending the decodingprocess in said decoding step.
 37. A computer readable memory mediumstoring a program for a signal processing method, said programcomprising: a communication step of receiving image data transmittedfrom a transmitting apparatus; an instruction step of giving aninstruction; a storage step of storing the image data in a storage; adisplay step of displaying an image corresponding to the image data; anda control step of controlling said communication step and said displaystep so as to request to said transmitting apparatus a transmission ofan image file including the image data currently in the course ofreception, when an instruction is provided in said instruction step in acourse of reception of said image data by said communication step anddisplay of said image data by said display step, and to receive theimage file transmitted from said transmitting apparatus in response tothe transmission request to output the received image file to saidstorage, while suspending the display process in said display step. 38.A computer readable memory medium storing a program for a signalprocessing method, said program comprising: a communication step ofreceiving plural information files and an information data streamcontained in said information files from a transmitting apparatus; aninstruction step of giving an instruction; and a control step ofcontrolling said communication step so as to request, in response to afirst instruction provided in said instruction step in a course ofreception of the information data stream in said communication step, atransmission of an information file including the information datastream currently in the course of reception, and to request atransmission of another information data stream in said pluralinformation files, other than the currently received information datastream.
 39. A computer readable memory medium storing a program for asignal processing method, said program comprising: an instruction stepof giving an instruction; a decoding step of decoding an informationdata stream; a communication step of receiving the information datastream transmitted from a transmitting apparatus, wherein saidcommunication step has a first mode for receiving the information datawhile decoding the information data, and a second mode for receiving theinformation data while suspending decoding of the information data; astorage step of storing in a storage the information data streamreceived by said communication step; and a control step of controllingsaid communication step so as to request in response to an instructionprovided in said instruction step in a course of reception of theinformation data stream in the first mode, a transmission of aninformation data file including the information data stream, to saidtransmitting apparatus and to receive the information data filetransmitted from said transmitting apparatus in response to thetransmission request in the second mode, to output the information datafile to said storage.